1. Field of the Invention
The present invention relates primarily to flashlights or lights powered by batteries.
2. Setting
Flashlights of various sizes and shapes are well known in the art. In particular certain of such known flashlights utilize two or more dry cell batteries, carried in a series usually in a cylindrical tube serving as a handle for the flashlight as a source of electrical energy. Typically an electrical circuit is established from one electrode of the battery through a conductor to a switch, then through a conductor to one electrode of the lamp bulb or globe. After passing through the filament of the lamp bulb the electrical circuit emerges through a second electrode of the lamp bulb and electrical contact with the conductor which in turn is in electrical contact with the flashlight housing. The power source for such flashlights can vary from typical dry cell batteries to plug-ins for cigarette lighters in automobiles.
Focusing features are provided on some available flashlights. However, retaining of the flashlight in a selected focusing position is dependent primarily on friction of the threads on one member which is fixed in relation to the light bulb and threads which are in a fixed position with respect to the lens. If the use is reasonably active, it is frequently not possible to retain the desired focusing of the light.